What Causes Engine Noise During Cold Start of the Encore?

[VonJaxson]

The reasons for engine noise during cold start of the Encore are as follows: Hydraulic Tappets: Due to low oil pressure or wear in the hydraulic tappets themselves, air enters the hydraulic tappets, causing noise. Valve Clearance: Wear in the valve rocker arms leads to excessive valve clearance. Carbon Canister Solenoid Valve Operation Sound: This is a normal sound and can continue to be used. If the sound is too loud, it is recommended to have it checked at a 4S shop. Three-Way Catalytic Converter: If there is noise within half a minute after a cold start, which then disappears, this is usually the sound of the three-way catalytic converter expanding after heating up.

[MacAlexis]

After driving for over a decade, I've seen too many cases of cold start abnormal noises like the Encore. The most common issue is the belt system—the alternator belt hardens and ages in low temperatures, while the tensioner pulley bearing grease solidifies, causing sharp friction sounds. Next, pay attention to oil fluidity, especially below zero degrees; switching from 0W20 to 5W30 oil can cause hydraulic lifter ticking. Then there's the plastic guide rail of the timing chain, which contracts in winter, increasing the gap and making the chain slapping noise particularly noticeable. The most hidden issue I've encountered is the lack of lubrication in the air conditioning compressor bearing, which sounds like fingernails scraping a blackboard during startup. I recommend using a long screwdriver to listen for the source of the noise by pressing it against different parts of the engine, focusing on checking belt tension and oil grade. Don't ignore this problem—last year, my neighbor's Cruze ended up needing a major repair due to neglecting a small abnormal noise.

[VanViolet]

After years of repairing cars, I've observed that about 80% of cold start noises in the Encore are maintenance-related. In winter, the worst thing is owners using summer engine oil to save trouble - at -10°C, the oil turns honey-thick, and if the camshaft can't get proper lubrication, how can it not make noise? Then there are those who haven't changed their belts in three years - the surfaces are full of cracks, stiff as plastic rulers when cold, squeaking and grinding against the pulleys. I've noticed northern owners need to pay special attention to coolant freezing points - failed antifreeze causes water pumps to grind dry. One customer complained his car started like a tractor - turns out the timing chain tensioner's seal had frozen and cracked. I recommend checking belt tensioner travel during oil changes, and replacing bearings immediately if pulleys make noise. Remember not to floor the accelerator before warming up - wait for RPMs to stabilize before driving.

[ChristopherLee]

Just went through this and let me talk about my car's condition. During that period, every cold start sounded like metal grinding, which scared me straight to the dealership. The mechanic used a stethoscope to locate the issue as a problem with the generator's rear bearing, where the grease solidified and caused sticking when cold. Another case involved the timing chain guide plate aging and cracking, making a rhythmic ticking sound like a metronome during each cold start. They recommended switching to full synthetic 0W20 oil first and observing for two weeks. Later, it was discovered that the deformed sealing ring on the oil filler cap caused oil vapor leakage, and surprisingly, replacing the cap for just thirty yuan solved the issue. Now, after developing a habit of warming up the car, there's basically no strange noise. I suggest northern car owners try to park in underground garages during winter.